WO2014157531A1 - Heat-ray control sheet - Google Patents

Abstract

The main purpose of the present invention is to provide a heat-ray control sheet whereby image ghosting is suppressed, excellent visibility is obtained, and the amount of heat rays can be controlled in accordance with the incidence angle of light. The present invention achieves the abovementioned purpose by providing a heat-ray control sheet characterized by having a light-transmitting part having a plurality of groove parts on one surface thereof, heat-ray absorbing parts formed in the groove parts of the light-transmitting part and including lanthanum hexaboride and antimony-doped tin oxide as heat-ray-absorbing particles, the content of lanthanum hexaboride in the heat-ray absorbing parts being no more than 0.8% by mass, and the content of antimony-doped tin oxide being no more than 8% by mass.

Description

Heat ray control sheet

The present invention relates to a heat ray control sheet having excellent visibility by suppressing generation of multiple images and capable of controlling a heat dose according to an incident angle of light.

In recent years, as environmental problems such as global warming become more serious, countermeasures are being promoted worldwide. Among them, for the purpose of energy saving and CO ₂ reduction, attention is focused on a method for controlling the space temperature of a house, an automobile, or the like using a heat ray control sheet, and development of the heat ray control sheet is being promoted.

The heat ray control sheet has a function of controlling the heat dose to be transmitted by absorbing light in the infrared region (hereinafter sometimes referred to as “infrared rays” or “heat rays”) among the light from the light source. For example, the functional sheet has a function of blocking heat ray intake into the room and suppressing an increase in the space temperature by being attached to a window glass or the like.
As such a heat ray control sheet, for example, Patent Document 1 discloses a “stacked type” sheet. FIG. 5 is a schematic cross-sectional view showing an example of a laminated type heat ray control sheet. As illustrated in FIG. 5, the stacked heat ray control sheet 50 is obtained by forming a heat ray shielding film 52 including particles (heat ray absorbing particles) 53 that absorb heat rays on a base material 51. According to Patent Document 1, the heat ray absorbing particles 53 are first inorganic fine particles 53a such as antimony-doped tin oxide (hereinafter sometimes abbreviated as ATO), and the second inorganic fine particles 53b are hexaboride. By using lanthanum (hereinafter sometimes abbreviated as LaB ₆ ) in combination, the transmittance of light in the visible light region (hereinafter sometimes referred to as “visible light”) is not reduced, It becomes possible to obtain a heat ray control sheet with improved absorption capacity.

However, such a laminated heat ray control sheet absorbs heat rays quantitatively regardless of the incident angle of light from the light source. For this reason, for example, when the heat ray control sheet is used for a window glass or the like, even in summer when it is desired to shield the heat ray to suppress the rise in the room temperature, even in the winter season when the heat ray is taken in to raise the room temperature. Since the heat dose absorbed by the control sheet is uniform, the heat dose taken into the room could not be adjusted according to the season.

On the other hand, Patent Document 2 discloses a “louver type” heat ray control sheet that selectively adjusts the heat dose by selectively transmitting or shielding heat rays according to the incident angle. As illustrated in FIG. 6, the louver type heat ray control sheet has a plurality of groove portions 103 formed in a straight line and in parallel in the light transmitting portion 101, and the groove portion 103 includes a heat ray absorbing portion containing heat ray absorbing particles. 102. By sticking the louver type heat ray control sheet 100 to the adherend 104 such as a window glass, it is possible to selectively transmit and shield the heat ray by utilizing the change in the incident angle of light with respect to the heat ray control sheet 100. it can.
Therefore, for example, in the case of using sunlight as a light source, the temperature rise in the interior of the vehicle or the interior of the vehicle is suppressed by reducing the intake of heat rays in the summer, and the interior of the vehicle or the interior of the vehicle by sufficiently capturing the heat rays in the winter. It is possible to suppress a temperature decrease such as.
In FIG. 6, the XY plane is the sheet surface of the heat ray control sheet, the X direction is the length direction, the Y direction is the width direction, and the Z direction is the thickness (groove depth) direction of the heat ray control sheet. Moreover, in FIG. 6, although the surface opposite to the surface which has a heat ray absorption part is made into the adherend side among the sheet | seat surfaces of a heat ray control sheet, the surface which has a heat ray absorption part is made into the adherend side. The same applies to the case.

In addition, the louver type heat ray control sheet can efficiently transmit not only the heat ray but also the visible ray according to the incident angle of light.
FIG. 7 is an explanatory diagram for explaining a light transmission path according to an incident angle of light in a louver type heat ray control sheet. 7 corresponds to a view of the heat ray control sheet 100 of FIG. 6 as viewed from the X direction, and is an aspect in which the heat ray control sheet 100 is attached to the adherend 104. The light source L in FIG. 7 is the sun.
For example, as illustrated in FIG. 7A, when the solar altitude is high as in summer, the incident angle (θ ₁ ) of sunlight increases, and sunlight from the side surface of the heat ray absorbing unit 102 increases. Incidence increases. At this time, visible light passes through the heat ray absorbing portion 102 and is taken into the adherend 104 side. On the other hand, the heat rays are absorbed by the heat ray absorbing particles contained in the heat ray absorbing portion 102, and thus the adherend 104. Side entry is blocked. That is, in summer indoors and the like, it is possible to secure the illuminance using visible light of sunlight and to suppress the increase in indoor temperature due to heat rays.
On the other hand, as illustrated in FIG. 7B, when the solar altitude is low as in winter, the incident angle (θ ₂ ) of sunlight is small. That is, since sunlight is incident from an angle close to perpendicular to the sheet surface of the heat ray control sheet 100, compared with the case of summer illustrated in FIG. The rate increases. In the light transmission part 101, since visible light and heat rays are transmitted, it can be taken into the adherend 104 side.
For this reason, in winter and the like, it is possible to secure both illuminance using visible light of sunlight and increase the indoor temperature due to heat rays.
Note that FIG. 7 shows a case where the surface having the heat ray absorbing portion among the sheet surfaces of the heat ray control sheet is on the light source side, but the same applies to the case where the sheet surface facing the surface is on the light source side.

JP 2000-169765 A JP 2011-69126 A

In the louver type heat ray control sheet, ATO is used as heat ray absorbing particles from the viewpoint of high light transmittance. However, if the amount of ATO used is increased in order to improve the heat ray absorption ability, the visibility of the appearance and the like seen from the adherend when the heat ray control sheet is used on an adherend such as a window glass is used. There is a problem that decreases. That is, when looking at the appearance etc. with the heat ray control sheet pasted on an adherend such as a window glass, a plurality of stripes parallel to the vertical direction enter the image reflected on the adherend, and in the direction in which the above streaks enter On the other hand, the phenomenon that the color of the image is decomposed and a rainbow-like unclear image appears. Such a phenomenon is not seen in the laminated type heat ray control sheet, and is unique to the louver type.
In the following description, an image in which colors appear to be separated in the direction of streaking is referred to as a “multiple image”.

The present invention has been made in view of the above circumstances, and provides a heat ray control sheet that has excellent visibility by suppressing the generation of multiple images and can control the heat dose according to the incident angle of light. The main purpose is to do.

In order to solve the above-mentioned problems, the present invention provides a light transmission part having a plurality of grooves on one surface, and lanthanum hexaboride and antimony doped as heat ray absorbing particles formed in the groove part of the light transmission part. A heat ray absorbing portion containing tin oxide, wherein the content of the lanthanum hexaboride in the heat ray absorbing portion is 0.8% by mass or less, and the content of the antimony-doped tin oxide is 8% by mass or less. There is provided a heat ray control sheet characterized by being.

According to the present invention, the heat-absorbing ability of the heat-absorbing part is obtained by adding lanthanum hexaboride having a high heat-absorbing ability to the predetermined amount of antimony-doped tin oxide as the heat-absorbing particles so as to have a predetermined content. The content of antimony-doped tin oxide can be reduced without lowering. As a result, the heat ray control sheet of the present invention can have high light transmittance without developing multiple images, and can control the heat dose according to the incident angle of light.

In the above invention, the content of the lanthanum hexaboride in the heat ray absorbing portion is preferably 0.6% by mass or less. This is because a decrease in visible light transmittance can be suppressed in the heat ray absorbing portion, and a heat ray control sheet having high transparency can be obtained.

In the above invention, the total sum of the content of the antimony-doped tin oxide and the content of the lanthanum hexaboride in the heat ray absorbing portion is preferably 4.2% by mass or more. Lanthanum hexaboride is about one-sixth the amount of antimony-doped tin oxide and exhibits the same heat ray absorption ability as antimony-doped tin oxide. Therefore, the total of the content of antimony-doped tin oxide and 6 times the addition amount of lanthanum hexaboride is 4.2% by mass or more, that is, when the antimony-doped tin oxide is used alone, the desired heat ray absorption ability is obtained. It is because it can be set as the amount more than required for showing, and it can be set as the heat ray | wire control sheet | seat which can maintain heat ray absorptivity and has the high light transmittance in which the expression of the multiple image was suppressed.

In the present invention, a heat ray absorbing portion obtained by adding a predetermined content of lanthanum hexaboride to antimony-doped tin oxide has a high heat ray absorbing ability and controls the heat dose according to the incident angle of light. It is possible to obtain a heat ray control sheet having excellent visibility in which the appearance of multiple images is suppressed.

It is a schematic perspective view which shows an example of the heat ray | wire control sheet | seat of this invention. It is the schematic sectional drawing seen from the X direction of FIG. It is a schematic diagram which shows an example of the heat ray absorption part in this invention. FIG. 5 is a correlation diagram between the content of heat ray absorbing particles and heat ray transmittance when LaB ₆ is used alone as a heat ray absorbing particle and when ATO is used alone. It is a schematic sectional drawing which shows an example of a lamination type heat ray | wire control sheet. It is a schematic diagram which shows an example of a louver type heat ray | wire control sheet | seat. It is explanatory drawing for demonstrating the light transmission path by the incident angle of light in a louver type heat ray | wire control sheet | seat.

Hereinafter, the heat ray control sheet of the present invention will be described in detail.

A. Heat ray control sheet The heat ray control sheet of this invention is demonstrated. The heat ray control sheet of the present invention includes a light transmission part having a plurality of grooves on one surface, and is formed in the groove part of the light transmission part, and includes lanthanum hexaboride and antimony-doped tin oxide as heat ray absorption particles. A heat ray absorbing part, wherein the content of the lanthanum hexaboride in the heat ray absorbing part is 0.8% by mass or less, and the content of the antimony-doped tin oxide is 8% by mass or less. It is what.

The heat ray control sheet of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view showing an example of the heat ray control sheet of the present invention, and FIG. 2 is a schematic cross-sectional view (longitudinal cross-sectional view) seen from the X direction of FIG. FIG. 3 is a schematic view showing an example of the heat ray absorbing portion in the present invention. In FIG. 1, the XY plane is the sheet surface of the heat ray control sheet, the X direction is the length direction of each part, the Y direction is the width direction of each part, and the Z direction is the thickness of the heat ray control sheet (the depth of the groove). A) direction.
As illustrated in FIGS. 1 and 2, the heat ray control sheet 10 of the present invention includes a light transmission part 1 having a plurality of groove parts 3 on one surface, and a heat ray absorption part 2 formed in the groove part 3. It has. Moreover, as illustrated in FIG. 3, the heat ray absorbing portion 2 in the present invention has a predetermined content of lanthanum hexaboride (LaB ₆ ) 21 and antimony-doped tin oxide (ATO) 22 as the heat ray absorbing particles 11. It is contained in.

In a general louver-type heat ray control sheet, ATO is generally used as heat ray absorbing particles from the viewpoint of heat ray absorption ability and good light transmittance.
In order for the heat ray control sheet to have high heat ray absorption ability, it is necessary to increase the content of ATO in the heat ray absorption part. However, as the ATO content increases, a multiple image appears on the heat ray control sheet when the louver type heat ray control sheet is used on an adherend such as a window glass, so that the appearance and the like are visible. There is a problem that decreases.

The following reasons are assumed as factors that cause multiple images to appear on the louver type heat ray control sheet.
When the content of ATO increases in the heat ray absorbing portion, the particles of ATO are likely to aggregate, and the light incident on the heat ray absorbing portion is scattered by hitting the aggregated ATO. On the other hand, since the light transmitting part does not contain particles such as ATO and light scattering does not occur, the light transmitted through the light transmitting part and the light transmitted through the light transmitting part and the heat ray absorbing part are diffused. Bias will occur. It is assumed that the image visually recognized through the heat ray control sheet becomes a multiple image due to the uneven diffusion of light.
Further, when the content of ATO increases, the refractive index difference increases at the interface between the heat ray absorbing portion including ATO and the light transmitting portion not including ATO. Therefore, when the light is transmitted, the visible light reflected at the interface repeatedly undergoes multiple reflections in the heat ray control sheet, and as a result, the reflected light and incident light cause interference phenomenon, resulting in multiple images. It is assumed.

Therefore, in order to prevent multiple images from appearing on the heat ray control sheet, it is necessary to reduce the amount of ATO contained in the heat ray absorption part. However, as described above, the reduction in the ATO content leads to a decrease in the heat ray absorption ability. Therefore, if the ATO content is reduced to the extent that multiple images do not appear, the heat dose absorbed in the heat ray absorption unit is also reduced. There exists a problem that it falls, and the original function as a heat ray | wire control sheet cannot fully be exhibited.

On the other hand, in the present invention, as heat ray absorbing particles, in addition to ATO, LaB ₆ having higher heat ray absorbing ability than ATO is added, and the heat ray control has a heat ray absorbing part in which each content is within a predetermined range. By using a sheet, the above-described problems have been solved.
LaB ₆ exhibits a heat-absorbing ability equivalent to that of ATO at a use amount of about one-sixth of ATO as will be described later. From this, by adding LaB ₆ , the content of ATO can be reduced to an amount that does not cause multiple images, that is, 8% by mass or less, without reducing the heat ray absorbing ability of the heat ray absorbing portion. it can. Thereby, it is possible to suppress the scattering of light due to the aggregation of ATO and the occurrence of multiple reflection at the interface between the light transmission part and the heat ray absorbing part, and it is possible to prevent multiple images from appearing on the heat ray control sheet. In addition, since the heat ray control sheet of the present invention maintains high heat ray absorption ability by adding LaB ₆ , even if the incident angle of light is large and the amount of light incident on the heat ray absorbing part is large, Can be sufficiently absorbed.

On the other hand, LaB ₆ exhibits a green color and has a defect that the light transmittance is lower than that of ATO. For this reason, if the amount of LaB ₆ added is excessively increased, the heat ray absorption ability is improved, but the heat ray control sheet may be colored by the green color exhibited by LaB ₆ and the light transmittance may be impaired. Therefore, in the present invention, by setting the content of LaB ₆ to 0.8% by mass or less, a heat ray control sheet having light transmittance equivalent to that when ATO is used alone as heat ray absorbing particles is used. It was possible.
Thus, the heat ray control sheet of the present invention has excellent visibility by suppressing the generation of multiple images by defining the heat ray absorbing particles contained in the heat ray absorbing portion, and the light incident angle. Accordingly, it becomes possible to control the heat dose taken into the room or the like.

“High heat ray absorption ability” means that the heat dose absorbed in the heat ray absorption part is large. That is, it means that the heat ray transmittance in the heat ray absorbing part is low and the heat dose taken into the room or the like is small.
Further, “low heat ray absorption ability” means that the heat dose absorbed in the heat ray absorbing portion is small. That is, it means that the heat ray transmittance in the heat ray absorbing part is high and the heat dose taken into the room or the like is large.

The present invention includes at least a light transmission part having a groove part and a heat ray absorption part.
Hereinafter, the heat ray control sheet of the present invention will be described for each part.

1. Heat ray absorbing portion First, the heat ray absorbing portion in the present invention will be described. The heat ray absorbing portion in the present invention is formed in the groove portion of the light transmitting portion and contains lanthanum hexaboride and antimony-doped tin oxide as heat ray absorbing particles, and the hexaboride in the heat ray absorbing portion. The content of lanthanum is 0.8% by mass or less, and the content of the antimony-doped tin oxide is 8% by mass or less.

(1) Heat-absorbing particles The content of ATO in the heat-absorbing part can absorb a desired heat dose in the heat-absorbing part by adding a predetermined amount of LaB ₆ described later, and the heat-ray control of the present invention The amount in which the sheet does not exhibit multiple images and has a desired visible light transmittance, that is, 8% by mass or less, preferably 4% by mass or less, with respect to 100% by mass of the total mass of the heat ray absorbing portion.
By setting the content of ATO to 8% by mass or less, the heat ray control sheet of the present invention can have a desired light transmittance, and the aggregation of ATO particles, the heat ray absorption part and the light transmission part Since multiple reflection at the interface is less likely to occur, it is possible to suppress the appearance of multiple images on the sheet.
In addition, as a minimum of content of ATO, it is preferable that it is 1 mass% or more, and it is preferable that it is 2 mass% or more especially. If the content of ATO is small, even if LaB ₆ is added, the amount of absorption of heat rays corresponding to the decrease in the content of ATO cannot be compensated, and the incident angle of light is particularly large and is incident on the heat ray absorption part. When there is a large amount of light, there is a possibility that heat rays cannot be absorbed sufficiently.

The content of LaB ₆ in the heat ray absorbing portion is an amount that can make the heat ray absorption amount in the heat ray absorbing portion as desired without lowering the visible light transmittance of the heat ray controlling sheet of the present invention, that is, It is 0.8 mass% or less with respect to 100 mass% of total mass of a heat ray absorption part, and it is preferable that it is 0.6 mass% or less especially. By setting the content of LaB ₆ to 0.8% by mass or less, even if the content of ATO is reduced to the above range or less, it is possible to maintain the heat ray absorption amount in the heat ray absorption part by LaB ₆ added. it can. Moreover, to be in the above range, the color of the LaB ₆ added heat-absorbing portion and it is possible to prevent the entire hot wire control sheet is colored, it is possible to have a high light transmittance. In particular, by setting the content of LaB ₆ to 0.6% by mass or less, a decrease in visible light transmittance can be suppressed in the heat ray absorbing portion, and a heat ray control sheet having high transparency can be obtained.
As the lower limit of the content of LaB _6, it is preferred preferably at least 0.01 wt%, it is inter alia 0.05 mass% or more. If the content of LaB ₆ is below the above lower limit, the amount of heat ray absorption corresponding to the decrease in the content of ATO cannot be compensated, especially when the incident angle of light is large and the amount of light incident on the heat ray absorbing portion is large. In addition, there is a possibility that heat rays cannot be sufficiently absorbed.

Moreover, about the heat ray absorptivity per unit mass of LaB ₆ and ATO, LaB ₆ can exhibit a heat ray absorptivity about 6 times that of ATO. Therefore, in the present invention, the sum of the content of ATO and 6 times the content of LaB ₆ is preferably 4.2% by mass or more, and more preferably 4.3% by mass or more. .
Hereinafter, this reason will be described in more detail.

FIG. 4 is a correlation diagram between the content of heat ray absorbing particles and heat ray transmittance when LaB ₆ is used alone as the heat ray absorbing particles and when ATO is used alone. FIG. 4 is based on the following verification results.

(Verification)
<Preparation of sample solution>
LaB ₆ content of 0.3 wt%, 0.5 wt%, so that 1.0 wt%, LaB ₆ dispersion (Sumitomo Metal Mining Co., Ltd. Product Name: KHF-7A toluene dispersion LaB ₆ content 1.85% by mass) and pentaerythritol triacrylate (product name: PET-30, manufactured by Nippon Kayaku Co., Ltd.), diluted with methyl ethyl ketone so that the solid content is 50% by mass, and then a photoinitiator (manufactured by BASF) Product name: Irgacure 184) was added in an amount of 4% by mass of pentaerythritol triacrylate to prepare three types of LaB ₆ sample solutions.
In addition, by using an ATO dispersion (Mitsubishi Materials Corporation MEK dispersion ATO content 20% by mass), two types of ATO sample liquids were prepared in a similar manner so that the ATO content was 5% by mass and 10% by mass. Prepared.

<Measurement of heat ray transmittance>
Three types of LaB ₆ sample solutions having LaB ₆ content of 0.3% by mass, 0.5% by mass, and 1.0% by mass are placed on a PET substrate (product name: A4100 100 μm thickness, manufactured by Toyobo Co., Ltd.) It was coated with a coater, dried in an oven at 70 ° C. for 30 seconds, and then UV cured in a nitrogen atmosphere to obtain three types of LaB ₆ coating films (film thickness: 10 μm).
Similarly, two types of ATO coating films (thickness: 10 μm) were obtained by the same method as the production method of LaB ₆ coating film using ATO content of 5 mass% and 10 mass% and two types of ATO sample solutions. .
For each coating film, an infrared visible ultraviolet spectrophotometer (UV3100PC, manufactured by Shimadzu Corporation) was used to measure the transmittance in the wavelength range of 800 nm to 2500 nm when the incident angle of light was 0 °. The average value was calculated. The average value of the transmittance was regarded as the heat ray transmittance, and the value of the heat ray transmittance (Y axis) against the content of the heat ray absorbing particles (X axis) was plotted.
Also, the heat-ray transmittance of the LaB _6, 2 times the content of LaB _6, 4 times, 6 times, was plotted in the same manner in terms of 8 times. Table 1 shows values of heat ray transmittances in the case of LaB ₆ alone (1 time amount) and ATO alone.

From FIG. 4, since the graph of the heat ray transmittance with respect to 6 times conversion of the LaB ₆ content is located on the straight line and the extension line of the graph of the heat ray transmittance with respect to the ATO content, LaB ₆ is 6 minutes of ATO. It can be said that a content of 1 shows equivalent heat ray transmittance.
In addition, when ATO is used alone in the heat ray absorbing portion, the heat ray absorption capacity of the heat ray control sheet is particularly high when the incident angle θ of light is 60 ° by setting the content to a predetermined amount or more. be able to. That is, as will be described later, the heat ray transmittance of the heat ray control sheet when the incident angle θ of light is 60 ° can be less than 35%.
Therefore, by setting the sum of the content of ATO and 6 times the content of LaB ₆ to 4.2% by mass or more, the heat ray transmittance when the light incident angle θ is 60 ° becomes less than 35%. It is possible to have a high heat ray absorbing ability.

The heat-absorbing particles are usually transparent and are preferably nanoparticles. The average particle diameter (D ₅₀ ) is, for example, preferably in the range of 10 nm to 200 nm, more preferably in the range of 20 nm to 150 nm, and particularly preferably in the range of 30 nm to 100 nm. . Further, if the average particle diameter is above the range of the ray absorbing particles, each having an average particle size of LaB ₆ and ATO may be equal, or may be one greater than the other.
When the average particle diameter of the heat ray absorbing particles is larger than the above range, haze is generated, and the transparency of the heat ray control sheet of the present invention may be lowered. On the other hand, if it is smaller than the above range, the dispersion stability and mass productivity of the heat-absorbing particles may be inferior.
The average particle size is a value obtained by measuring the particle size distribution by the dynamic light scattering method. The average particle diameter can also be obtained by observing the particles of the heat-absorbing particles with an electron microscope and arithmetically averaging. The preferred average particle diameter range at this time is the same as the above-mentioned range.

(2) Other materials It is preferable that the heat ray absorption part in this invention has binder resin at least other than the heat ray absorption particle mentioned above.
The binder resin in the heat ray absorbing part is not particularly limited as long as it is a material that can be cured by irradiation with ionizing radiation. The ionizing radiation may be classified by the quantum energy of the electromagnetic wave, but in the present invention, all ultraviolet rays (UV-A, UV-B, UV-C), visible rays, γ rays, X rays, electron rays are used. Means active energy rays.
The binder resin material is preferably an ionizing radiation curable resin polymerized mainly with a monomer, oligomer, prepolymer or polymer having a radical polymerizable active group in the structure, and the ionizing radiation curable resin. Examples of the resin include an ultraviolet curable resin, an electron beam curable resin, a visible light curable resin, and a near infrared curable resin. In the present invention, it is particularly preferable to use an ultraviolet curable resin and an electron beam curable resin. Specifically, reactive oligomers such as epoxy acrylate, urethane acrylate, polyether acrylate, polyester acrylate, polythiol, vinyl pyrrolidone, 2-ethylhexyl acrylate, β-hydroxy acrylate, tetrahydrofurfuryl acrylate, etc. Reactive monomers such as 2-hydroxy-3-acryloyloxypropyl methacrylate, polyethylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, etc. Etc.

The binder resin preferably contains a photoinitiator. This is because the binder resin can be cured by irradiation with ionizing radiation such as ultraviolet rays having a wavelength of 300 nm to 400 nm. The photoinitiator can be appropriately selected according to the type of ionizing radiation to be irradiated. An acylphosphine oxide photoinitiator such as Irgacure 907, specifically, Lucirin TPO, Irgacure 819, or the like can be used. The content of the photoinitiator can be appropriately adjusted according to the amount of the binder resin. For example, the content of the photoinitiator is within a range of about 0.1 to 5 parts by mass with respect to 100 parts by mass of the binder resin. It is preferable that

The binder resin in the heat ray absorbing portion preferably has a small refractive index with respect to visible light. This is because ATO and LaB ₆ have a large refractive index of light in the visible light region, so that the refractive index of the entire heat-absorbing portion can be adjusted by reducing the refractive index of the binder resin.

The binder resin content in the heat ray absorbing part is preferably in the range of 40% by mass to 98% by mass with respect to the total mass (100% by mass) of the heat ray absorbing part. It is preferably within the range of 95% by mass. When the content of the binder resin is larger than the above range, the concentration of the heat ray absorbing particles may become thin and the heat ray may not be sufficiently absorbed. On the other hand, when the content is smaller than the above range, the adhesiveness to the light transmitting part is poor. There is.

In addition to the heat ray absorbing particles and the binder resin described above, the heat ray absorbing portion can have a photoinitiator, an ultraviolet absorber, a light stabilizer, a polymerization inhibitor, an antifoaming agent, and the like.

(3) Heat ray absorbing portion The heat ray absorbing portion preferably has a desired refractive index with respect to visible light, and is preferably close to the refractive index with respect to visible light in the light transmitting portion. Specifically, the refractive index of the heat ray absorbing portion is preferably in the range of 1.40 to 1.80, more preferably in the range of 1.45 to 1.70, particularly 1.50 to 1.70. It is preferable to be within the range of 1.65. When the refractive index with respect to visible light of the heat ray absorbing portion is within the above range, the difference in refractive index with the light transmitting portion is reduced, and a heat ray control sheet with high visibility in which the appearance of multiple images is suppressed can be obtained. .
In addition, as a measuring method of the refractive index of a heat ray absorption part, it can obtain by the measuring method of the refractive index prescribed | regulated to JISK7142. Specifically, it can be measured by an Abbe refractometer (manufactured by Atago Co., Ltd.) using a sodium light source with a measurement wavelength of 589 nm under the condition of a temperature of 23 ° C.

Since the heat ray absorbing portion in the present invention is formed by filling the material of the heat ray absorbing portion described above in the groove portion in the light transmitting portion, the heat ray absorbing portion is usually the same shape as the shape of the groove portion. Become.
Examples of the longitudinal cross-sectional shape of the heat ray absorbing portion include a triangle, a square, a rectangle, a trapezoid, and a shape having four curved sides. Moreover, according to the shape of a groove part, the corner | angular part of the said heat ray absorption part may have a curved surface, and the side surface of the said heat ray absorption part may be a curve instead of a straight line.
In addition, the shape of the heat ray absorbing portion viewed from the sheet surface is not particularly limited, and may be, for example, a straight shape or a curved shape. Furthermore, arrangement | positioning of the said heat ray absorption part seen from the sheet | seat surface of the heat ray | wire control sheet | seat of this invention is not specifically limited, You may arrange | position in parallel and may arrange in parallel. , May be randomly arranged in the other direction. As a heat ray absorption part seen from the sheet | seat surface of the heat ray | wire control sheet | seat of this invention, what is arrange | positioned in parallel at linear form is suitable.

The height of the heat ray absorbing portion can be appropriately set depending on the desired size of the heat ray control sheet, and is preferably in the range of 10 μm to 300 μm, for example, and in particular in the range of 25 μm to 250 μm. In particular, it is preferably in the range of 50 μm to 200 μm. By setting the height of the heat ray absorbing portion within the above range, for example, light having a large incident angle such as summer sunlight is likely to be incident on a wide range of the surface of the heat ray absorbing portion, so that more heat rays are generated. This is because the temperature rise in the room or the like can be suppressed by being absorbed.
Further, the height of the heat ray absorbing portion described above is preferably in the range of 50% to 100% with respect to the thickness of the light transmitting portion described later, and in particular, in the range of 60% to 95%. In particular, it is preferable to be within the range of 70% to 90%. This is because if the height of the heat ray absorbing portion is smaller than the above range with respect to the thickness of the light transmitting portion, the thickness of the heat ray control sheet is relatively increased and the flexibility may be lowered. In addition, the height of the heat ray absorbing portion is a portion indicated by T1 in FIG.

The width of the heat ray absorbing portion is preferably in the range of 5 μm to 50 μm, more preferably in the range of 7 μm to 45 μm, and particularly preferably in the range of 10 μm to 40 μm. If the width of the heat ray absorbing part is larger than the above range, it may be difficult to transmit visible light as the whole heat ray absorbing part and the heat ray control sheet. On the other hand, if the width is smaller than the above range, the height of the heat ray absorbing part may be as described above. In some cases, the heat ray absorbing portion cannot absorb a sufficient heat dose, and the desired heat ray absorbing ability cannot be exhibited. In addition, the width | variety of a heat ray absorption part is a part shown by W in FIG.

The length of the heat ray absorbing portion is appropriately selected according to the desired size of the heat ray control sheet. In addition, the length of the said heat ray absorption part means the length extended in the X direction in FIG.

The pitch width of the heat ray absorbing portion is preferably in the range of 30 μm to 200 μm, more preferably in the range of 40 μm to 150 μm, and particularly preferably in the range of 50 μm to 110 μm. When the pitch width of the heat ray absorbing part is larger than the above range, light having a large incident angle is difficult to enter the heat ray absorbing part, and the heat ray may not be sufficiently absorbed. On the other hand, if it is smaller than the above range, visible light may not be easily transmitted through the light transmission part. In addition, the pitch width of the said heat ray absorption part is a part shown by P in FIG.

As the method for forming the heat ray absorbing portion, for example, the heat ray absorbing portion forming composition containing the above-described heat ray absorbing portion material can be filled in the groove portion of the light transmitting portion and cured.

The viscosity of the composition for forming a heat ray absorbing portion may be any viscosity that can be used in a coating method described later. Specifically, the viscosity is preferably in the range of about 100 Cps to 20000 Cps, more preferably in the range of about 250 to 10000 Cps, and particularly preferably in the range of about 500 to 5000 Cps. If the viscosity of the composition for forming a heat ray absorbing part is higher than the above range, the coating method described later may not be used. Moreover, when lower than the said range, the shape after apply | coating the composition for heat ray absorption part formation and making it harden | cure may not be able to be hold | maintained.

The method for applying the composition for forming a heat ray absorbing portion is not particularly limited as long as it is a method capable of sufficiently filling at least the groove portion with the composition for forming a heat ray absorbing portion. As a specific coating method, a wiping method, a coating method, a dry laminating method, an extrusion laminating method, or the like can be used. Among them, the coating method is preferable from the viewpoint of productivity, the precision of the coated film, and the like. As the coating method, applicator coating, Miya bar coating, wire bar coating, gravure coating, die coating and the like can be used.
Further, when the composition for forming a heat ray absorbing part is applied, an excessive amount of the composition for forming a heat ray absorbing part flowing out from the groove part to the surface of the light transmitting part may be removed by scraping with a squeegee or the like. Good.

As the curing method of the composition for forming a heat ray absorbing portion, curing by irradiation with ionizing radiation is preferable. The type of ionizing radiation is the same as the content described in the above-mentioned section “(2) Other materials”, and thus the description thereof is omitted here. Moreover, about the hardening conditions etc. of the composition for heat ray absorption part formation, it can set suitably according to the kind of composition for heat ray absorption part formation, and the kind of ionizing radiation to be used.

2. Light transmitting portion The light transmitting portion in the present invention has a plurality of grooves on one surface. In the light transmission part, both visible light and heat rays are transmitted.

The material used for the light transmission part is preferably a material that is cured by irradiation with ionizing radiation, that is, an ionizing radiation curable resin. The ionizing radiation is the same as that described in the section “1. Examples of the ionizing radiation curable resin include an ultraviolet curable resin, an electron beam curable resin, a visible light curable resin, a near infrared curable resin, and the like. Among them, an ultraviolet curable resin and an electron beam curable resin are used. It is preferable.

As the ultraviolet curable resin and the electron beam curable resin, it can be appropriately selected from conventionally used polymerizable oligomers or prepolymers. Examples thereof include polymerizable oligomers or prepolymers, and particularly polyfunctional polymerizable oligomers or prepolymers. Examples of the polymerizable oligomer or prepolymer include oligomers and prepolymers having a radically polymerizable unsaturated group in the molecule, such as epoxy (meth) acrylate, urethane (meth) acrylate, and polyether urethane (meth) acrylate. Examples include caprolactone-based urethane (meth) acrylate, polyester (meth) acrylate-based, polyether (meth) acrylate-based oligomers and prepolymers, and these may be used alone or in combination of two or more. In the present invention, “(meth) acrylate” means “acrylate or methacrylate”.

In addition, when polyfunctional urethane (meth) acrylate is used as the material used for the light transmission part, for the purpose of adjusting its viscosity, it is not suitable for monofunctional (meth) acrylate such as methyl (meth) acrylate. A diluent can be used in combination. The monofunctional (meth) acrylate may be used alone or in combination of two or more, or a low molecular weight polyfunctional (meth) acrylate may be used in combination. Moreover, as a diluent, applicability | paintability can also be ensured using said monomer.

In addition, when an ultraviolet curable resin is used as the material for the light transmission part, it is preferable to use a photopolymerization initiator in combination. As the type of the photopolymerization initiator, those conventionally used can be used. The content of the photopolymerization initiator in the light transmission part is preferably in the range of about 0.1 parts by mass to 5 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin.

The light transmission part may contain a weather resistance improver such as an ultraviolet absorber (UVA) in order to further improve the weather resistance. The ultraviolet absorber may be inorganic or organic. Examples of inorganic ultraviolet absorbers include titanium oxide, cerium oxide, and zinc oxide. The average particle size (D ₅₀ ) of the inorganic ultraviolet absorber is preferably in the range of about 5 nm to 120 nm. Moreover, as an organic type ultraviolet absorber, a benzotriazole type | system | group, a triazine type | system | group, a benzophenone type | system | group, a salicylate type | system | group, an acrylonitrile type | system | group, etc. can be used, for example, A triazine type is preferable. This is because the ultraviolet ray absorbing ability is high, and it is difficult to deteriorate against high energy such as ultraviolet rays.

In addition to the above-mentioned materials, the light transmission part includes hard coat properties, light stabilizers, scratch-resistant fillers, polymerization inhibitors, crosslinking agents, antistatic agents, adhesion improvers, antioxidants, leveling agents, thixotropic agents. Further, additives such as a coupling agent, a plasticizer, an antifoaming agent and a filler may be contained.

The light transmission part has a plurality of grooves on one surface. Since the heat ray absorbing portion described above is formed in the groove portion, the shape of the groove portion and the shape of the heat ray absorbing portion are the same.
The shape, size, and the like of the groove are the same as those described in the section “1. Heat-absorbing part” described above, and thus the description thereof is omitted here.

The thickness of the light transmission part is appropriately selected according to the thickness of the target heat ray control sheet and the shape of the groove part, etc., but is preferably in the range of 10 μm to 300 μm, and more preferably 25 μm to It is preferably in the range of 250 μm, particularly preferably in the range of 50 μm to 200 μm. When the thickness of the light transmission part is larger than the above range, light loss due to absorption of light incident on the light transmission part occurs, and the visibility of the heat ray control sheet of the present invention is reduced or The thickness of the heat ray control sheet may increase and the flexibility may decrease. On the other hand, if it is smaller than the above range, it may be difficult to form a groove having a desired shape.
The thickness of the light transmission part is a part indicated by T2 in FIG.

The visible light transmittance of the light transmission part is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. Generation of light loss due to absorption of light incident on the light transmission portion can be suppressed, and the visibility of the heat ray control sheet can be increased. On the other hand, if the visible light transmittance is lower than the above range, the visible light transmittance of the entire heat ray control sheet of the present invention is also lowered. May not be ensured, and the illuminance in the room may be insufficient.
Regarding the method for measuring the visible light transmittance of the light transmission part, a spectrophotometer (“UV-2450” manufactured by Shimadzu Corporation, JIS K 0115 compliant product) was used, and a Toyobo PET film (product number: Cosmo). This is confirmed by measuring a 10 μm-thick light transmission part formed on Shine A4300 (thickness 100 μm) within a measurement wavelength range of 380 nm to 780 nm.

Further, the refractive index of the light transmitting part is appropriately adjusted according to the refractive index of the heat ray absorbing part, but is preferably in the range of 1.40 to 1.80, for example 1.45. Is preferably in the range of ˜1.70, and particularly preferably in the range of 1.50 to 1.65.
By setting the refractive index of the light transmitting part within the above range, it is possible to suppress the occurrence of light reflection and refraction at the interface with the heat ray absorbing part, so that the light is transmitted through the heat ray absorbing part and the light transmitting part. The attenuation of visible light can be suppressed. Thereby, it is possible to reduce the deviation of the emitted light between the visible ray transmitted through the heat ray absorbing portion and the light transmitting portion and the visible ray transmitted through the light transmitting portion, and to suppress the appearance of multiple images in the heat ray control sheet. Is possible.
In addition, as a measuring method of the refractive index of a light transmissive part, it can measure by the method similar to the method demonstrated in the term of "1. Heat ray absorption part (3) Heat ray absorption part" mentioned above.

A method for forming the light transmitting portion is not particularly limited as long as the thickness of the light transmitting portion is within a desired range and a plurality of groove portions can be formed.
Specifically, the light transmitting portion-forming composition comprising the light transmitting portion material described above is applied to the shaping plate having the convex portions, the coating film is cross-linked and cured, and the shaping plate is peeled to release the light. A transmission part can be formed.
When using a base material, the composition for forming a light transmission part may be applied onto the base material to form a coating film, and then the shaping plate may be pressed and cured by crosslinking. The plate may be disposed so as to face each other, and the composition for forming a light transmission part may be injected therebetween to be crosslinked and cured.
Furthermore, as another method, a layer separately formed using the composition for forming a light transmission part may be stacked on a shaping plate or may be bonded.
The shaped plate has a plurality of convex portions on the surface, and the shape and size of the convex portions are usually the same as the shape of the groove portions. Further, the shape of the shaping plate is not particularly limited, and examples thereof include a plate shape and a roll shape.

The viscosity of the composition for forming a light transmission part is not particularly limited as long as it has a viscosity that can be used in a coating method described later, and is preferably in the range of, for example, about 500 Cps to 5000 Cps. In addition, although the said composition for light transmissive part formation does not contain a solvent normally, in order to acquire applicability | paintability, you may dissolve the material of the light transmissive part mentioned above in the solvent etc. .

The method for applying the composition for forming a light transmission part is not particularly limited as long as it can be applied so as to have a uniform film thickness. As such a coating method, for example, a spin coating method, a die coating method, a dip coating method, a bar coating method, a gravure printing method, a screen printing method, or the like can be used.

As a curing method of the composition for forming a light transmission part, curing by irradiation with ionizing radiation as described above is preferable, and ultraviolet rays or electron beams are preferably used from the viewpoint of practicality.
Moreover, about hardening conditions etc., it can set suitably according to the kind of composition for light transmissive part formation.

3. Other Configurations The heat ray control sheet of the present invention has at least the light transmission part and the heat ray absorption part described above, but other parts as long as the visibility and heat ray absorption ability of the heat ray control sheet are not deteriorated. You may have. Hereinafter, the site | part assumed in this invention is demonstrated.

(1) Base material The heat ray | wire control sheet | seat of this invention may have the base material which can hold | maintain the shape of the whole heat ray | wire control sheet | seat.
The substrate is not particularly limited as long as it has high light transmittance and does not adversely affect the visibility of the heat ray control sheet. As such a substrate, a sheet-like or film-like one made of a transparent resin can be used, and among them, a film-like substrate (hereinafter sometimes referred to as a film substrate) is preferably used. It is done.

The film substrate may be any material as long as it has transparency to light in the visible light region and has strength to support the light transmission part and the heat ray absorption part. For example, polyethylene terephthalate, polycarbonate, polyester, polyurethane Resin films such as polyvinyl alcohol, polycarbonate, vinyl chloride, fluororesin, and rubber can be used. Of these, polyethylene terephthalate and polycarbonate resin films are preferred in terms of transparency and strength. Moreover, the said film base material may contain antioxidant, a ultraviolet absorber, etc.

In addition, the said base material may perform the surface treatment etc. on the single side | surface or both surfaces as needed. As the above-mentioned surface treatment, surface treatment by an oxidation method such as corona discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone ultraviolet irradiation treatment, and surface treatment by an uneven method such as a sand blast method or a solvent treatment method. Chemical surface treatment or the like can be used.

The thickness of the substrate can be appropriately selected depending on the purpose of use, but it is usually preferably in the range of 5 μm to 200 μm, and more preferably in the range of 10 μm to 150 μm. If it is too thin, curls and wrinkles are likely to occur, and the heat ray control sheet of the present invention may not have the desired strength.

The visible light transmittance of the substrate is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. If the visible light transmittance of the substrate is lower than the above range, the visible light transmittance of the entire heat ray control sheet of the present invention is also lowered. There may be cases where lighting cannot be secured and the illuminance in the room is insufficient.

(2) Adhesive layer The heat ray control sheet of the present invention may have an adhesive layer in order to adhere to an adherend such as a window glass.
As a material of the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer, any material having weather resistance may be used. For example, acrylic, urethane, silicon, rubber, or the like can be used. Among them, it is preferable to use an acrylic pressure-sensitive adhesive mainly composed of a polymer or copolymer of an acrylic monomer such as acrylic acid ester or methacrylic acid ester as a material having light resistance, and in particular, n-butyl acrylate. 2-ethylhexyl acrylate or the like is preferably used.

Moreover, it is preferable that the said adhesion layer contains the ultraviolet absorber. This is because the weather resistance of the pressure-sensitive adhesive layer can be improved by containing the ultraviolet absorber.
The ultraviolet absorber may be either inorganic or organic, and an ultraviolet absorber having a reactive group in the molecule can also be used. As the inorganic ultraviolet absorber, titanium oxide, cerium oxide, zinc oxide or the like having an average particle diameter of about 5 to 120 nm can be preferably used. Moreover, as an organic type ultraviolet absorber, a benzotriazole type, a triazine type, a benzophenone type, a salicylate type, an acrylonitrile type etc. can be mentioned preferably, for example. Of these, triazines are preferable because they have a high ability to absorb ultraviolet rays and do not easily deteriorate even with high energy such as ultraviolet rays.

The content of the ultraviolet absorber in the pressure-sensitive adhesive layer is preferably in the range of 0.1 to 25 parts by weight, more preferably in the range of 1 to 25 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive. In particular, it is preferably in the range of 3 to 20 parts by mass.

The adhesive layer may contain a light stabilizer and the like. This is because the weather resistance of the adhesive layer can be improved.
The light stabilizer is preferably a hindered amine light stabilizer or the like, and may have a reactive group in the molecule. Examples of the light stabilizer include 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1,2 , 2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 2,4-bis [N-butyl-N- (1- And cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) amino] -6- (2-hydroxyethylamine) -1,3,5-triazine.

The content of the light stabilizer in the pressure-sensitive adhesive layer is preferably in the range of 0.05 to 7 parts by weight, more preferably in the range of 0.5 to 5 parts by weight, with respect to 100 parts by weight of the pressure-sensitive adhesive. It is more preferable that the content be within the range of 1 to 5 parts by mass.

The position where the adhesive layer is formed can be appropriately selected according to the usage mode of the heat ray control sheet of the present invention. For example, when the heat ray control sheet is used for internal application, it is preferably formed on the surface of the light transmission part including the surface of the heat ray absorption part. On the other hand, when using the said heat ray control sheet for external sticking, it is preferable to form on the surface of the light transmissive part which does not include the surface of a heat ray absorption part, or on a base material. The thickness of the adhesive layer is preferably in the range of 5 μm to 100 μm, and more preferably in the range of 10 μm to 75 μm.

The adhesive layer is prepared by, for example, diluting the above-mentioned adhesive layer material with a solvent such as ethyl acetate or toluene to prepare a coating solution having a solid content of 20% by mass to 60% by mass, and applying the coating solution to a release sheet or the like. It can form by sticking to the surface which has at least one of a light transmissive part or a heat ray absorption part.
In the above-described forming method, as a method of applying the coating solution for the adhesive layer, for example, a knife coater, a comma coater, a gravure coater, a roll coater or the like can be used. In the case of using the coating method, the coating amount of the material of the adhesive layer is in the range of ^{10g / m 2 ~ 30g / m} 2 by dry weight is preferred. By setting it within the above range, sufficient adhesion to the adherend can be obtained, and no sticking layer sticks out during processing.

(3) Release layer When the heat ray | wire control sheet | seat of this invention has an adhesion layer, you may have a release layer on the adhesion layer.
This is because by having the release layer, dust or the like can be prevented from adhering to the adhesive layer, and deterioration of the visibility of the heat ray control sheet due to dirt can be prevented. In addition, in the case where the heat ray control sheet of the present invention is formed into a roll shape, it is possible to prevent the occurrence of unwinding failure such as roughening of the adhesive surface during unwinding.

The material used for the release layer is not particularly limited as long as it is generally used. Specific examples include acrylic and methacrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl chloride resins, cellulose resins, silicone resins, chlorinated rubber, casein, various surfactants, metal oxides, and the like. Or what mixed 2 or more types can be used.

(4) Protective layer It is preferable that the heat ray | wire control sheet | seat of this invention has a protective layer from viewpoints, such as a weather resistance and scratch resistance. Examples of the protective layer include a weather resistant layer, a hard coat layer, a weather resistant hard coat layer, and a self-cleaning layer.

As a material for the protective layer, an ionizing radiation curable resin is preferably used. The ionizing radiation curable resin can be appropriately selected from a polymerizable oligomer or prepolymer, and among them, a polyfunctional polymerizable oligomer or prepolymer is preferably used. Examples of the polymerizable oligomer or prepolymer include oligomers and prepolymers having radically polymerizable unsaturated groups in the molecule, such as epoxy (meth) acrylate, urethane (meth) acrylate, and polyether urethane (meth) acrylate. And caprolactone-based urethane (meth) acrylate, polyester (meth) acrylate-based, polyether (meth) acrylate-based oligomers and prepolymers, etc., in particular, polyfunctional urethane (meth) acrylate-based It is preferable in terms of achieving both hard coat properties, and a molecular weight of about 1000 to 5000 is preferable.
Here, (meth) acrylate refers to acrylate or methacrylate.

In addition to the above polyfunctional polymerizable oligomer, the ionizing radiation curable resin includes a caprolactone urethane (meth) acrylate obtained by a reaction of a caprolactone polyol, an organic isocyanate and a hydroxy acrylate, and a polybutadiene oligomer side. A polymer urethane (meth) acrylate such as a highly hydrophobic polybutadiene (meth) acrylate having a (meth) acrylate group in the chain can be used in combination. It is because the weather resistance of a protective layer can be improved by using together. Among these, it is preferable to use a caprolactone-based material in combination.

In addition, when polyfunctional urethane (meth) acrylate is used as a material for the protective layer, a diluent such as monofunctional (meth) acrylate such as methyl (meth) acrylate is used for the purpose of adjusting the viscosity. Can be used together. The monofunctional (meth) acrylate may be used alone or in combination of two or more, or a low molecular weight polyfunctional (meth) acrylate may be used in combination. Moreover, as a diluent, applicability | paintability can also be ensured using said monomer.

The material for the protective layer can contain an ultraviolet absorber, a light stabilizer, a flaw resistant filler such as silica particles, a silicate compound, and the like. In addition, about the specific ultraviolet absorber and light stabilizer, the same kind as what was mentioned above can be used.

The thickness of the protective layer is preferably within a range of 0.1 μm to 20 μm, more preferably within a range of 0.5 μm to 10 μm, and particularly preferably within a range of 1 μm to 8 μm. It is because it can protect, without reducing the visibility of the heat ray | wire control sheet | seat of this invention, etc. by making thickness of a protective layer into the said range.

As a method for forming the protective layer, for example, a coating solution obtained by diluting the above-described protective layer material with a desired solvent may be prepared, and the coating solution may be applied to the surface of the heat ray control sheet.
In the above-described forming method, as a method for applying the coating solution for the protective layer, for example, an applicator coat, a beer bar coat, a wire bar coat, a gravure coater, a die coater, or the like can be used.

The position where the protective layer is disposed is appropriately selected according to the application mode of the heat ray control sheet of the present invention, and when the heat ray control sheet of the present invention is attached to the adherend, usually, It arrange | positions so that it may become the outermost layer of the said heat ray | wire control sheet | seat with respect to a to-be-adhered body.

(5) Others The heat ray control sheet of the present invention may have, for example, a flattening layer, a scattering layer, and the like on the surfaces of the heat ray absorption part and the light transmission part in addition to the above-described parts. This is because it is possible to suppress the occurrence of the light diffraction phenomenon and the light interference phenomenon in the heat ray control sheet, and to prevent the visibility from being lowered due to the appearance of multiple images. Moreover, you may have a photocatalyst layer for the purpose of control of an air chamber. The planarizing layer preferably has the same optical characteristics as the light transmission part.

4). Heat ray control sheet The heat ray control sheet of the present invention preferably has a small difference in refractive index of light in the visible light region at the interface between the heat ray absorbing portion and the light transmitting portion. By making the difference in the refractive index of visible light between the heat ray absorbing part and the light transmitting part small, it is possible to suppress the occurrence of multiple reflections of visible light at the interface and to form a heat ray control sheet that hardly produces multiple images. Because you can.
The refractive index difference between the heat ray absorbing portion and the light transmitting portion in the present invention is preferably in the range of 0.001 to 0.050, and more preferably in the range of 0.001 to 0.030. In particular, it is preferably in the range of 0.001 to 0.020.
In addition, the refractive index of visible light of a heat ray control sheet is confirmed by measuring by the method similar to the method demonstrated by the term of "1. heat ray absorption part (3) heat ray absorption part" mentioned above.

The heat ray control sheet of the present invention is not particularly limited as long as it has light transmittance and excellent visibility, but for example, the total light transmittance is preferably 70% or more.
Here, the total light transmittance is a value measured using a fully automatic direct reading haze computer (HGM-2DP) manufactured by Suga Test Instruments Co., Ltd.

Further, the visible light transmittance of the heat ray control sheet of the present invention is preferably high regardless of the incident angle of light, but usually the appearance is observed from an adherend such as a window glass on which the heat ray control sheet is stuck. In this case, since the angle formed by the observer, the heat ray control sheet, and the observation object is approximately 0 °, the visible light transmittance when the light incident angle is 0 ° is preferably in a desired range. Specifically, the visible light transmittance when the incident angle of light is 0 ° is preferably 65% or more, more preferably 70% or more, and particularly preferably 75% or more.
By setting the visible light transmittance to the above range when the incident angle of light is 0 °, the appearance and the like can be clearly observed. In addition, since the amount of visible light taken into the room or the like increases, the illuminance in the room can be secured using light from the light source.

The heat ray transmittance of the heat ray control sheet of the present invention is preferably set as appropriate according to the incident angle of light. That is, it is preferable to have a heat ray transmittance according to the season.
For example, in the summer, the heat ray control sheet is required to exhibit a high heat ray absorbing ability from the viewpoint of preventing an increase in indoor temperature due to heat rays taken into the room from the window glass. That is, it is preferable that the heat ray transmittance of the heat ray control sheet is low. Specifically, the heat ray transmittance when the light incident angle is 60 ° is preferably 50% or less, more preferably 40% or less, and particularly preferably less than 35%.
On the other hand, in the winter season, it is required that the heat ray control sheet exhibits a low heat ray absorbing ability because it is possible to increase the room temperature by taking in a lot of heat rays from the window glass into the room. . That is, it is preferable that the heat ray transmittance of the heat ray control sheet is high. Specifically, the heat ray transmittance when the incident angle of light is 0 ° is preferably 35% or more, more preferably 40% or more, and particularly preferably 50% or more.

The visible light transmittance of the heat ray control sheet was measured by using a infrared visible ultraviolet spectrophotometer (UV3100PC, manufactured by Shimadzu Corporation) and measuring the spectral transmittance in a wavelength range of 380 nm to 780 nm according to JIS A5759-2008. , Calculated by the calculation formula stipulated in the same standard. The heat ray transmittance is an average value of transmittance in a wavelength range of 800 nm to 2500 nm when measured by a method according to the same standard.

The diffraction efficiency of the heat ray control sheet of the present invention is preferably small. If the diffraction efficiency is large, the light diffracted in the heat ray control sheet increases, so that the diffracted light interferes with each other, resulting in a difference in light intensity for each wavelength, resulting in an increase in the appearance of multiple images. It is. Specifically, the diffraction efficiency of the heat ray control sheet is preferably 35% or less, and more preferably 30% or less.
In the present invention, the diffraction efficiency means that when only a 0th-order light of the diffracted light is passed through a 1 cm square slit located 50 cm away from the heat ray control sheet using a laser having a wavelength of 633 nm. The value calculated by the equation (1) from the intensity I ₁ (mW) of the laser light immediately after passing through the heat ray control sheet and the intensity I ₂ (mW) of the 0th-order light after passing through the slit.

Further, the heat ray control sheet of the present invention preferably has a low haze value, for example, preferably 20% or less, more preferably 10% or less, and particularly preferably 5% or less. When the haze value is higher than the above range, the transparency of the heat ray control sheet becomes low, and the visibility may be lowered when the heat ray control sheet is attached to an adherend such as a window glass. In addition, the said haze value is confirmed by measuring according to JISK7136.

As a use mode of the heat ray control sheet of the present invention, it can also be used as “for internal application” to be applied to the inside of the adherend, that is, the indoor side, and can also be applied to the outside of the adherend, that is, the outdoor side. It can also be used as an “outside paste”.
In addition, the heat ray control sheet is attached to the adherend so that the sheet surface including the surface of the heat ray absorbing portion becomes the light incident surface in any of the usage modes of “inner bonding” or “outer bonding”. Alternatively, the surface facing the sheet surface including the surface of the heat ray absorbing portion may be attached to the adherend so as to be the light incident surface.

5. Manufacturing method As a manufacturing method of the heat ray control sheet of the present invention, as long as it is a method capable of forming an aspect having a light transmission part having a plurality of grooves on one surface and a heat ray absorption part formed in the groove, It is not particularly limited.
As an example of the manufacturing method, a composition for forming a light transmission part is applied to a shaping plate having a convex part that is an inverted shape of a groove part, and cured by irradiation with ionizing radiation or the like to form a light transmission part having a groove part. Subsequently, a method of forming the heat ray absorbing portion by filling the groove portion with the composition for forming the heat ray absorbing portion and curing it by irradiation with ionizing radiation or the like can be mentioned. In addition, since the formation method of each part is the same as the content demonstrated in the item of each part mentioned above, description here is abbreviate | omitted.

6). Applications The heat ray control sheet of the present invention can adjust the amount of absorption of heat rays while securing lighting according to the incident angle of light from the light source, and can control the rise and fall of the indoor temperature. Therefore, for example, it can be used by being attached to a window such as a building, a house, a train, a car, a bus, a window glass, an opening, or the like of an airplane or a ship.

Note that the present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Hereinafter, examples and comparative examples will be shown to describe the present invention in more detail.

[Example 1]
(Preparation of mold)
A plurality of convex portions that are linear in the circumferential direction along the surface direction, the main cutting surface is a rectangle having a height of 150 μm, and a width of 25 μm on the plate surface side are arranged in parallel with each other at a pitch width of 105 μm. A roll mold was prepared.

(Formation of light transmission part having groove part)
A PET film (product name: A4100 manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm was used as a base material, and a light transmission part forming composition having the following composition was applied to one surface of the base material.

<Light transmission part forming composition>
・ Ethoxylated bisphenol A diacrylate (m + n = 3) (Product name: ABE-300, Shin-Nakamura Chemical Co., Ltd.) 40 parts by mass ・ Ethoxylated bisphenol A diacrylate (m + n = 10) (Product name: A-BPE-10) Shin-Nakamura Chemical Co., Ltd.) ... 60 parts by mass, 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) ... 4 parts by mass

Ultraviolet rays from an ultraviolet irradiation device (Fusion UV System Japan Co., Ltd., light source D bulb) are used as a base material, with the applied composition for forming a light transmission part sandwiched between the mold and the base material. By irradiating from the side, the composition for forming a light transmission part was crosslinked. After that, by releasing the mold, a light transmission part having a groove part on the surface of which a plurality of linearly connected grooves in one direction along the surface direction was formed on one side of the substrate. In addition, the shape of the groove portion was an inverted shape of the convex portion of the mold described above.

(Preparation of LaB ₆ dispersion resin)
4 g of KHDS-06 (powder containing 21.5% by mass of LaB _6; manufactured by Sumitomo Metal Mining Co., Ltd.) and 39 g of 2-hydroxy-3-acryloyloxypropyl methacrylate (product name: 701A manufactured by Shin-Nakamura Chemical Co., Ltd.) Then, 86 g of zirconia beads (2 mmφ) was placed in a glass bottle and dispersed in a paint shaker for 4 hours to obtain a LaB ₆ dispersion resin (LaB ₆ concentration 2%) having an average particle diameter (D ₅₀ ) of 88 nm.
The average particle size of the LaB ₆ dispersed resin is a value obtained by measuring the particle size distribution by a dynamic light scattering method using Microtrac UPA (manufactured by Nikkiso Co., Ltd.). At this time, the background was methyl ethyl ketone and diluted with methyl ethyl ketone for measurement. In addition, it is the value measured by the same method also about the average particle diameter of the ATO particle | grains in the ATO ink used for the composition for heat ray absorption part formation mentioned later.

(Preparation of composition A for forming a heat-absorbing part)
Next, using a LaB ₆ dispersed resin described above to adjust the heat-absorbing portion forming composition A having the following composition.

<Heat ray absorbing part forming composition A>
LaB ₆ dispersion resin: 30 parts by mass ATO ink (ATO particles (average particle size 52 nm) 20% by mass, UV curable resin composition (containing photopolymerization initiator) 80% by mass) 40 mass parts 2-hydroxy- 3-acryloyloxypropyl methacrylate (product name: 701A, Shin-Nakamura Chemical Co., Ltd.) 27.7 parts by mass, 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) 2.3 parts by mass

(Formation of heat ray absorption part)
The composition A for forming a heat ray absorbing part is applied to the surface having the groove part of the light transmitting part, the coating film is squeezed with an iron doctor blade, and only the composition for forming the heat ray absorbing part applied to the region other than the groove part is scraped off. The heat ray absorbing part forming composition was filled only in the groove part. By irradiating ultraviolet rays from an ultraviolet irradiation device (light source D bulb manufactured by Fusion UV System Japan Co., Ltd.), the composition for forming a heat ray absorbing portion in the groove portion was crosslinked and cured to form a heat ray absorbing portion. In addition, the shape of the said heat ray absorption part was the same as that of the groove | channel part mentioned above.

(Formation of planarization layer)
The above resin composition for a light transmitting part was applied on the surface having the heat ray absorbing part of the light transmitting part so as to have a thickness of about 20 μm and UV-cured to form a flattened layer to obtain a heat ray control sheet.

[Example 2]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition B for forming a heat ray absorbing part having the following composition was used.

<Composition B for forming a heat ray absorbing part>
LaB ₆ dispersion resin 30 parts by mass ATO ink (ATO particles (average particle size 52 nm) 10% by mass, UV curable resin composition (containing photopolymerization initiator) 90% by mass) 40 parts by mass 2-hydroxy- 3-acryloyloxypropyl methacrylate (product name: 701A, Shin-Nakamura Chemical Co., Ltd.) 27.7 parts by mass, 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) 2.3 parts by mass

[Example 3]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition C for forming a heat ray absorbing part having the following composition was used.

<Heat ray absorbing part forming composition C>
LaB ₆ dispersion resin: 40 parts by mass ATO ink (ATO particles (average particle size: 52 nm) 10% by mass, UV curable resin composition (containing photopolymerization initiator) 90% by mass): 40 parts by mass 2-hydroxy- 3-acryloyloxypropyl methacrylate (product name: 701A, Shin-Nakamura Chemical Co., Ltd.) 17.7 parts by mass, 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) ... 2.3 parts by mass

[Example 4]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the heat ray absorbing part forming composition D having the following composition was used.

<Composition D for forming a heat ray absorbing portion>
LaB ₆ dispersion resin: 10 parts by mass ATO ink (ATO particles (average particle size: 52 nm) 10% by mass, UV curable resin composition (containing photopolymerization initiator) 90% by mass): 80 parts by mass 2-hydroxy- 3-acryloyloxypropyl methacrylate (product name: 701A, Shin-Nakamura Chemical Co., Ltd.) ... 9.2 parts by mass, 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) ... 0.8 parts by mass

[Example 5]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition E for forming a heat ray absorbing part having the following composition was used.

<Composition E for forming a heat-absorbing part>
LaB ₆ dispersion resin: 20 parts by mass ATO ink (ATO particles (average particle size: 52 nm) 10% by mass, UV curable resin composition (containing photopolymerization initiator) 90% by mass): 40 parts by mass 2-hydroxy- 3-acryloyloxypropyl methacrylate (product name: 701A, Shin-Nakamura Chemical Co., Ltd.) 37.7 parts by mass, 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) 2.3 parts by mass

[Example 6]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition F for forming a heat ray absorbing part having the following composition was used.

<Composition F for forming a heat ray absorbing part>
・ LaB ₆ dispersion resin: 0.5 parts by mass. ATO ink (ATO particles (average particle size: 52 nm): 20% by mass, UV curable resin composition (containing photopolymerization initiator): 80% by mass): 40 parts by mass: Bisphenol A Type Epoxy Acrylate (Product name: EA-1020, Shin-Nakamura Chemical Co., Ltd.) 40 parts by mass 2-hydroxy-3-acryloyloxypropyl methacrylate (Product name: 701A, Shin-Nakamura Chemical Co., Ltd.) ... 17.2 parts by mass 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) 2.3 parts by mass

[Example 7]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition G for forming a heat ray absorbing part having the following composition was used.

<Heat ray absorbing part forming composition G>
-LaB ₆ dispersion resin ... 30 parts by mass-ATO ink (ATO particles (average particle size 52 nm) 20% by mass, UV curable resin composition (containing photopolymerization initiator) 80 mass%) ... 10 parts by mass-Bisphenol A type epoxy Acrylate (Product name: EA-1020, Shin-Nakamura Chemical Co., Ltd.) ... 40 parts by mass 2-hydroxy-3-acryloyloxypropyl methacrylate (Product name: 701A, Shin-Nakamura Chemical Co., Ltd.) ... 16.5 parts by mass, 1- Hydroxy-cyclohexyl-phenyl-ketone (Product name: Irgacure184 manufactured by BASF) 3.5 parts by mass

[Example 8]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition H for forming a heat ray absorbing part having the following composition was used.

<Heat ray absorbing part forming composition H>
-LaB ₆ dispersion resin: 10 parts by mass-ATO ink (ATO particles (average particle size 52 nm) 20% by mass, UV curable resin composition (containing photopolymerization initiator) 80 mass%) ... 20 parts by mass-Bisphenol A type epoxy Acrylate (Product name: EA-1020, Shin-Nakamura Chemical Co., Ltd.) ... 40 parts by mass 2-hydroxy-3-acryloyloxypropyl methacrylate (Product name: 701A, Shin-Nakamura Chemical Co., Ltd.) ... 26.9 parts by mass, 1- Hydroxy-cyclohexyl-phenyl-ketone (Product name: Irgacure184, manufactured by BASF) 3.1 parts by mass

[Example 9]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition I for forming a heat ray absorbing part having the following composition was used.

<Composition I for forming a heat ray absorbing portion>
-LaB ₆ dispersion resin: 30 parts by mass-ATO ink (ATO particles (average particle size: 52 nm) 20% by mass, UV curable resin composition (containing photopolymerization initiator) 80 mass%): 5 parts by mass-Bisphenol A type epoxy Acrylate (Product name: EA-1020, Shin-Nakamura Chemical Co., Ltd.) ... 40 parts by mass 2-hydroxy-3-acryloyloxypropyl methacrylate (Product name: 701A, Shin-Nakamura Chemical Co., Ltd.) ... 21.3 parts by mass, 1- Hydroxy-cyclohexyl-phenyl-ketone (Product name: Irgacure184, manufactured by BASF) 3.7 parts by mass

[Example 10]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition J for forming a heat ray absorbing part having the following composition was used.

<Heat ray absorbing part forming composition J>
-LaB ₆ dispersion resin: 2.5 parts by mass-ATO ink (ATO particles (average particle size 52 nm) 20% by mass, UV curable resin composition (containing photopolymerization initiator) 80% by mass) ... 20 parts by mass-Bisphenol A Type Epoxy Acrylate (Product name: EA-1020 Shin-Nakamura Chemical Co., Ltd.) ... 40 parts by mass 2-hydroxy-3-acryloyloxypropyl methacrylate (Product name: 701A Shin-Nakamura Chemical Co., Ltd.) 34.4 parts by mass 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) 3.1 parts by mass

[Example 11]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition K for forming a heat ray absorbing part having the following composition was used.

<Heat ray absorbing part forming composition K>
-LaB ₆ dispersion resin: 0.5 parts by mass-ATO ink (ATO particles (average particle size 52 nm) 20% by mass, UV curable resin composition (containing photopolymerization initiator) 80% by mass) ... 20 parts by mass Type epoxy acrylate (Product name: EA-1020, Shin-Nakamura Chemical Co., Ltd.) 40 parts by mass 2-hydroxy-3-acryloyloxypropyl methacrylate (Product name: 701A, Shin-Nakamura Chemical Co., Ltd.) 36.4 parts by mass 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) 3.1 parts by mass

[Example 12]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition L for forming a heat ray absorbing part having the following composition was used.

<Heat ray absorbing part forming composition L>
-LaB ₆ dispersion resin: 0.5 parts by mass-ATO ink (ATO particles (average particle size 52 nm) 20% by mass, UV curable resin composition (containing photopolymerization initiator) 80% by mass) ... 15 parts by mass Type Epoxy Acrylate (Product name: EA-1020, Shin-Nakamura Chemical Co., Ltd.) 40 parts by mass 2-hydroxy-3-acryloyloxypropyl methacrylate (Product name: 701A, Shin-Nakamura Chemical Co., Ltd.) 41.2 parts by mass 1-hydroxy-cyclohexyl-phenyl-ketone (product name: Irgacure184, manufactured by BASF) ... 3.3 parts by mass

[Comparative Example 1]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition M for forming a heat ray absorption part having the following composition was used.

<Composition M for forming a heat ray absorbing part>
ATO ink (ATO particles (average particle size 52 nm) 10% by mass, UV curable resin composition (containing photopolymerization initiator) 90% by mass) ... 100 parts by mass

[Comparative Example 2]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition N for forming a heat ray absorbing part having the following composition was used.

<Composition N for forming a heat ray absorbing portion>
ATO ink (ATO particles (average particle size 52 nm) 20% by mass, UV curable resin composition (containing photopolymerization initiator) 80% by mass) ... 100 parts by mass

[Comparative Example 3]
A heat ray control sheet was obtained in the same manner as in Example 1 except that the composition O for forming a heat ray absorbing part having the following composition was used.

<Heat-absorbing part forming composition O>
-LaB ₆ dispersion resin: 45 parts by mass-ATO ink (ATO particles (average particle size 52 nm) 20% by mass, UV curable resin composition (containing photopolymerization initiator) 80 mass%) ... 20 parts by mass-Bisphenol A type epoxy Acrylate (Product name: EA-1020, Shin-Nakamura Chemical Co., Ltd.) 31.9 parts by mass, 1-hydroxy-cyclohexyl-phenyl-ketone (Product name: Irgacure184, manufactured by BASF) 3.1 parts by mass

Regarding the heat ray control sheets of Examples 1 to 12 and Comparative Examples 1 to 3, the contents of LaB ₆ and ATO in the total mass (100% by mass) of the heat ray absorbing part are shown in Table 2.

(Sample for evaluation)
On the flattened layer of the heat ray control sheets of Examples 1 to 12 and Comparative Examples 1 to 3, an optical adhesive material (product name: LUCIACS CS9621T manufactured by Nitto Denko Corporation) was used and bonded to a glass plate (3 mm thickness). A sample for evaluation was used.
[Evaluation 1]
(Visual evaluation)
The following items were visually evaluated on the heat ray control sheets of Examples 1 to 12 and Comparative Examples 1 to 3.
<Appearance>
The degree of blurring (degree of appearance of multiple images) was evaluated visually. The case where the image could be visually recognized without inconvenience was indicated as ◯, and the case where multiple images appeared and the image was noticeably blurred was indicated as X.
<Color>
The degree of color was evaluated visually. The case where there was no inconvenience in coloring the heat ray control sheet was indicated by ○, and the case where the heat ray control sheet was markedly colored was indicated by ×.

(Diffraction efficiency)
The heat ray control sheets of Examples 1 to 12 and Comparative Examples 1 to 3 are attached to a frame, and a diffracted light beam is slit into a 1 cm square slit located 50 cm away from the heat ray control sheet using a laser having a wavelength of 632.8 nm. Only the 0th order light was allowed to pass through. In this case, the intensity I ₁ of the laser beam immediately after passing through the heat ray control sheet _(mW), and was determined to 0 the intensity of the primary light I _{2 (mW)} after passing through the slit. Next, diffraction efficiency was calculated from the following formula (1) using the measured I ₁ (mW) and I ₂ (mW).

(Visible light transmittance and heat ray transmittance)
With respect to the heat ray control sheets of Examples 1 to 12 and Comparative Examples 1 to 3, the visible light transmittance and the heat ray transmittance were measured when the light incident angles were 0 ° and 60 °. Visible light transmittance is specified in the same standard by measuring spectral transmittance in a wavelength range of 380 nm to 780 nm according to JIS A5759-2008 using an infrared visible ultraviolet spectrophotometer (UV3100PC manufactured by Shimadzu Corporation). It is a value calculated by the following calculation formula. The heat ray transmittance is an average value of transmittance in a wavelength range of 800 nm to 2500 nm when measured by a method according to the same standard. The measurement when the incident angle of light with respect to the heat ray control sheet was 60 ° was performed by inclining the specimen.

The results of the above evaluation are shown in Table 3.

As shown in Examples 1 to 12, by setting the LaB ₆ content in the heat-absorbing part to 0.8% by mass or less and the ATO content to 8% by mass or less, multiple images can be expressed in visual evaluation. Further, no visual hindrance was observed due to coloring of the heat ray control sheet. In particular, when the LaB ₆ content is 0.6% by mass or less, the visible light transmittance is 70% or more when the incident angle θ of light is 0 °, and the appearance of multiple images is not confirmed. Therefore, it was possible to have good visibility. Further, by making the sum of the content of ATO and 6 times the content of LaB ₆ 4.2 mass% or more, the heat ray transmittance when the light incident angle θ is 60 ° is less than 35%, It was possible to have high heat ray absorption ability.
On the other hand, Comparative Examples 1 and 2 are heat ray absorbing parts containing only ATO, and the content thereof is more than 8% by mass, so that the visible light transmittance is high when the light incident angle θ is 0 °. Multiple images were remarkably exhibited and the visibility was poor.
In Comparative Example 3, LaB ₆ and ATO were used in combination, and the ATO content was 8% by mass or less. Thus, multiple images were not observed, but the LaB ₆ content was 0.00. Since it was more than 8% by mass, the heat ray control sheet exhibited LaB ₆ color, and the visible light transmittance was low when the incident angle θ of light was 0 °, and the visibility was poor.

1 ... light transmission part 2 ... heat absorbing part 3 ... groove 11 ... heat-absorbing particles 21 ... lanthanum hexaboride _(LaB 6)
22 ... Antimony-doped tin oxide (ATO)
10 ... Heat ray control sheet

Claims (3)

1. A light transmission part having a plurality of grooves on one surface;
   Formed in the groove of the light transmitting portion;
   A heat ray absorbing portion containing lanthanum hexaboride and antimony-doped tin oxide as heat ray absorbing particles,
   The heat ray controlling sheet, wherein the content of the lanthanum hexaboride in the heat ray absorbing portion is 0.8% by mass or less and the content of the antimony-doped tin oxide is 8% by mass or less.
2. The heat ray control sheet according to claim 1, wherein the content of the lanthanum hexaboride in the heat ray absorption part is 0.6% by mass or less.
3. The sum of the content of the antimony-doped tin oxide and the content of the lanthanum hexaboride in the heat ray absorbing portion is 4.2% by mass or more. 3. The heat ray control sheet according to item 2.

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